US20090219256A1 - Systems and Methods for Resolving Multitouch Scenarios for Optical Touchscreens - Google Patents
Systems and Methods for Resolving Multitouch Scenarios for Optical Touchscreens Download PDFInfo
- Publication number
- US20090219256A1 US20090219256A1 US12/368,372 US36837209A US2009219256A1 US 20090219256 A1 US20090219256 A1 US 20090219256A1 US 36837209 A US36837209 A US 36837209A US 2009219256 A1 US2009219256 A1 US 2009219256A1
- Authority
- US
- United States
- Prior art keywords
- light
- touch
- detector
- distance
- shadow
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/042—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by opto-electronic means
- G06F3/0421—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by opto-electronic means by interrupting or reflecting a light beam, e.g. optical touch-screen
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/0416—Control or interface arrangements specially adapted for digitisers
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2203/00—Indexing scheme relating to G06F3/00 - G06F3/048
- G06F2203/041—Indexing scheme relating to G06F3/041 - G06F3/045
- G06F2203/04104—Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2203/00—Indexing scheme relating to G06F3/00 - G06F3/048
- G06F2203/041—Indexing scheme relating to G06F3/041 - G06F3/045
- G06F2203/04111—Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
Definitions
- the present subject matter pertains to touch display systems that allow a user to interact with one or more processing devices by touching on or near a surface.
- FIG. 1 illustrates an example of an optical/infrared-based touch detection system 100 that relies on detection of light traveling in optical paths that lie in one or more detection planes in an area 104 (“touch area” herein) above the touched surface.
- FIG. 2 features a perspective view of a portion of system 100 .
- optical imaging for touch screens can use a combination of line-scan or area image cameras, digital signal processing, front or back illumination, and algorithms to determine a point or area of touch.
- two light detectors 102 A and 102 B are positioned to image a bezel 106 (represented at 106 A, 106 B, and 106 C) positioned along one or more edges of the touch screen area.
- Light detectors 102 which may be line scan or area cameras, are oriented to track the movement of any object close to the surface of the touch screen by detecting the interruption of light returned to the light detector's field of view 110 , with the field of view having an optical center 112 .
- the light can be emitted across the surface of the touch screen by IR-LED emitters 114 aligned along the optical axis of the light detector to detect the existence or non existence of light reflected by a retro-reflective surface 107 along an edge of touch area 104 via light returned through a window 116 .
- the retroreflective surface along the edges of touch area 104 returns light in the direction from which it originated.
- the light may be emitted by components along one or more edges of touch area 104 that direct light across the touch area and into light detectors 102 in the absence of interruption by an object.
- an object 118 (a stylus in this example) is interrupting light in the detection plane, the object will cast a shadow 120 on the bezel ( 106 A in this example) which is registered as a decrease in light retroreflected by surface 107 .
- light detector 102 A would register the location of shadow 120 to determine the direction of the shadow cast on border 106 A, while light detector 102 B would register a shadow cast on the retroreflective surface on bezel portion 106 B or 106 C in its field of view.
- FIG. 3 illustrates the geometry involved in the location of a touch point T relative to touch area 104 of system 100 .
- touch point T can be triangulated from the intersection of two lines 122 and 124 .
- Lines 122 and 124 correspond to a ray trace from the center of a shadow imaged by light detectors 102 A and 102 B to the corresponding detector location in detector 102 A and 102 B, respectively.
- the borders 121 and 123 of one shadow are illustrated with respect to light detected by detector 102 B.
- the distance W between light detectors 102 A and 102 B is known, and angles ⁇ and ⁇ can be determined from lines 122 and 124 .
- FIG. 4 shows two touch points T 1 and T 2 and four resulting shadows 126 , 128 , 130 , and 132 at the edges of touch area 104 .
- Point T 1 can be triangulated from respective centerlines of shadows 126 and 128 as detected via light detectors 102 A and 102 B, respectively.
- Point T 2 can be triangulated from centerlines of shadows 130 and 132 as detected via light detectors 102 A and 102 B, respectively.
- shadows 126 and 132 intersect at G 1 and shadows 128 and 130 intersect at G 2 , and the centerlines of the shadows can triangulate to corresponding “ghost” points, which are all potential touch position coordinates.
- these “ghost points” are indistinguishable from the “true” touch points at which light in the touch area is actually interrupted.
- ghost points and true touch points can be distinguished from one another without resort to additional light detectors.
- a distance from a touch point to a single light detector can be determined or estimated based on a change in the length of a shadow detected by a light detector when multiple light sources and/or differing patterns of light are used. The distance can be used to validate one or more potential touch position coordinates.
- the shadow cast due to interruption of a first pattern of light from a primary light source can be measured. Then, a second pattern of light can be used to illuminate the touch area.
- the change in length of the shadow will be proportional to the distance from the point of interruption (i.e., the touch point) to the light detector.
- the second pattern of light may be emitted from a secondary light source or may be emitted by changing how light is emitted from the primary light source.
- Distances from possible touch points as determined from triangulation can be considered alongside the distance determined from shadow extension to determine which possible touch points are “true” touch points and which ones are “ghost” touch points.
- FIG. 1 is a block diagram illustrating an exemplary conventional touch screen system.
- FIG. 2 is a perspective view of the system of FIG. 1 .
- FIG. 3 is a diagram illustrating the geometry involved in calculating touch points in a typical optical touch screen system.
- FIG. 4 is a diagram illustrating the occurrence of “ghost points” when multiple simultaneous touches occur in an optical touch screen system.
- FIG. 5 is a block diagram illustrating an exemplary touch detection system configured in accordance with one or more aspects of the present subject matter.
- FIGS. 6A and 6B illustrate changes in shadows cast by different touch points due to interruption of light from a secondary illumination source.
- FIGS. 7A and 7B illustrate the relationship between shadow extension length and light detector distance in closer detail.
- FIG. 8 is a flowchart showing an exemplary method of resolving a multitouch scenario.
- FIG. 9 is a diagram illustrating distances between potential touch points and estimated distances for actual touch points.
- FIG. 10 is a block diagram illustrating an exemplary touchscreen system.
- FIG. 5 is a block diagram illustrating an exemplary touch detection system 200 configured in accordance with one or more aspects of the present subject matter.
- two optical units 202 A and 202 B are positioned at comers of a touch area 204 bounded on three sides by a retroreflective bezel 206 having portions 206 A, 206 B, and 206 C.
- Each optical unit 202 can comprise a light detector such as a line scan sensor, area image camera, or other suitable sensor.
- the optical units 202 also comprise a primary illumination system that emits light to illuminate a retroreflector that (in the absence of any interruptions in the touch area) returns the light to its point of origin. See, for instance, U.S. Pat. No. 6,362,468, which is incorporated by reference herein in its entirety.
- the light detector of each optical unit 202 has a field of view 210 with an optical center shown by ray trace 212 .
- the position of an interruption in the pattern of detected light relative to the optical center can be used to determine a direction of a shadow relative to the optical unit.
- an interruption of light at a point in touch area 204 can correspond to a first shadow detected by one detector (e.g., the detector of optical unit 202 A) and a second shadow detected by a second detector (e.g., the detector of optical unit 202 B).
- the position of the interruption relative to touch area 204 can be determined.
- FIG. 5 also illustrates a secondary illumination system 208 .
- Secondary illumination system 208 comprises one or more sources of light positioned a known distance from the detector of optical unit 202 B (and the detector of optical unit 202 A). As illustrated by ray trace 213 , secondary illumination system 208 emits light off-center relative to the optical center of the detector of either optical unit 202 A or 202 B in this example.
- both the primary and secondary illumination systems could be off-center relative to a detector.
- the secondary illumination may be on-center while the primary illumination is off-center.
- FIGS. 6A and 6B illustrate changes in shadows cast by a touch point T due to interruption of light from a primary illumination source associated with optical unit 202 A and secondary illumination source 208 .
- an interruption due to touch point T casts a shadow S 1 having edges 214 and 216 .
- An angle ⁇ can be determined based on a centerline 218 of shadow S 1 .
- FIG. 6B shows that the illumination in touch area 204 has changed. Namely, light from secondary source 208 is emitted as represented by dotted lines 220 .
- the detector of optical unit 202 A images the resulting shadow cast due to the interruption at touch point T. Since secondary illumination source 208 is off-center relative to the detector of optical unit 202 A, a different shadow is cast. Specifically, in this example, a larger shadow is cast, with the difference in shadow length along the edge of touch are 204 illustrated at dS. This lengthening effect is due to the fact that the shadow from the field of view of detector 202 A has edges 214 and 222 . Centerline 218 of the original shadow S 1 is shown for reference.
- FIGS. 7A and 7B illustrate the geometry of the shadow length extension in closer detail for a case in which point T is relatively close to the detector of optical unit 202 A (shown in FIG. 7A ) and a case in which point T is farther from the detector of optical unit 202 A (shown in FIG. 7B ).
- illumination from secondary illumination source 208 is represented as ray traces 220 and 221 along with shadow edges 214 and 222 as seen in the field of view of detector 202 A.
- Original shadow edge 216 i.e. the shadow edge when light from the primary illumination system is interrupted
- S 1 and shadow extension dS are shown for reference, along with the boundaries of S 1 and shadow extension dS.
- FIGS. 7A and 7B include an inset illustrating distances dA (the distance between secondary illumination source 208 and the detector of optical unit 202 A); distance dY (the length of one side of touch area 204 ), shadow extension length dS, and a length dX along the side of touch area 204 opposite length dA (but not necessarily equal to dA).
- An angle ⁇ is shown representing the angle between the top side of touch area 204 and original shadow edge 216 ; this angle may be derived using a ray trace of the original shadow boundaries.
- An angle ⁇ circumflex over (-) ⁇ is also illustrated as formed from the intersection between shadow edge 216 and ray trace 221 .
- shadow edge 216 and ray trace 221 can be treated as a proxy for the position of touch point T.
- portion rA of ray trace 216 can be treated as an estimate of the distance from the detector of optical unit 202 A to touch point T.
- FIGS. 7A and 7B show that as the distance rA from T to optical unit 212 A varies, the length dS varies, with dS being larger if T is closer to the detector in this example. Different patterns of light may result in dS becoming shorter as T moves closer to the detector, so the use of shadow “lengthening” in this example is not meant to be limiting.
- Ray traces 221 and 216 form two sides of an upper triangle and a lower triangle.
- the third side of the upper triangle has a length equal to dA and the third side of the lower triangle has a length equal to dS.
- One side of the upper triangle has a length rA, while one side of the lower triangle has a length rB.
- the distance RA from point P to optical unit 212 B can be calculated or estimated as:
- rB can be expressed as a function of rA since the total length (rA+rB) from detector 202 B to the bottom edge of touch area 204 is easily computed as the hypotenuse of a third (right) triangle formed by ray trace 216 (whose total length is RA+RB), vertical side Y (whose length is dY) of touch area 204 (which is known), and horizontal side having a length dX:
- the distance rA is referred to as an “estimation” because, in practice, the accuracy of the shadow length may vary with the distance of the interruption from the detector. This phenomenon is related to the variations in detection accuracy that can occur based on relative position in the touch area as is known in the art. Additionally, in this example, the intersection between ray 220 and 216 does not correspond to the center of point T.
- FIG. 8 is a flowchart showing an exemplary method 300 for resolving a multitouch scenario based on a distance determined using a secondary illumination system.
- FIG. 9 is a diagram illustrating distances between potential touch points and estimated ranges for actual touch points and will be discussed alongside FIG. 9 .
- potential touch coordinates which in this example are calculated from triangulating shadows.
- this is for purposes of example only, and in embodiments one or more potential touch coordinates could be identified in any other suitable fashion and then validated using a technique based on shadow extension.
- a distance from the detector of to each of the four potential touch points is calculated.
- Four potential touch points can be identified based on the directions of shadows cast by simultaneous interruptions in light traveling across the touch area. For example, a first pattern of light may be used for determining the four points from triangulation.
- FIG. 9 shows an example of four shadows having centerlines 901 , 902 , 903 , and 904 .
- a first shadow SA- 1 having a centerline 901 results from an interruption of light at a first point TA in the touch area and is detected using a first detector (i.e. the detector of optical unit 202 A).
- a second shadow SA- 2 having a centerline 902 also results from the interruption at point PA and is detected using the detector of optical unit 202 B.
- a third shadow SB- 1 having a centerline 903 and a fourth shadow SB- 2 having a centerline 904 are created by an interruption at point TB simultaneous to the interruption at point TA and are detected using the first and second detectors, respectively.
- two interruptions may be considered “simultaneous” if the interruptions occur within a given time window for light detection/touch location.
- the interruptions may occur the same sampling interval or over multiple sampling intervals considered together.
- the interruptions may be caused by different objects (e.g., two fingers, a finger and a stylus, etc.) or different portions of the same object that intrude into the detection area at different locations, for example.
- FIG. 9 also illustrates actual touch points “TA” and “TB” as solid circles.
- the relative position of the actual touch points to the potential touch points is not known to the touch detection system, however.
- the actual touch points may of course coincide with potential touch points but are shown in FIG. 9 as separate from potential touch points for purposes of illustrating exemplary method 300 , which can be used to determine which triangulated touch points actually correspond to the interruptions in the touch area.
- Block 302 in FIG. 8 represents calculating a distance from one of the detectors to each of the four potential touch points P 1 -P 4 .
- This distance (DistanceN) can be determined, for example, using the triangulated coordinates (X,Y) for each point (PN) using the following expression:
- DISTANCE N ⁇ square root over ( X N 2 +Y N 2 ) ⁇
- Block 304 of FIG. 8 represents calculating an estimated distance from the detector to each of the two touch points based on identifying a shadow extension. This can be determined based on comparing the patterns of light detected by a single detector under a first illumination condition (e.g., a first pattern of light, such as a pattern of light from the detector's primary illumination source) and then changing the illumination to a second pattern of light (e.g., by illuminating using a secondary illumination system while the primary illumination is not used or changing the pattern of light emitted from the primary illumination system).
- a first illumination condition e.g., a first pattern of light, such as a pattern of light from the detector's primary illumination source
- a change in length of shadow SA- 1 could be determined.
- a change in length of shadow SB- 1 could be determined.
- a distance from each point to the detector can be determined using the expression solved above for rA based on the length of the respective shadow extensions as compared to the distance between the detector and the light source used to emit the second pattern of light.
- the actual ranges can be considered alongside the calculated ranges for the potential touch points P 1 -P 4 to determine which touch points are actual touch points.
- a distance metric can be calculated for use in identifying the “actual” touch points.
- a distance metric is used in some embodiments since a direct comparison between the calculated ranges and the ranges as determined by shadow length changes may lead to ambiguous results. For example, the coordinates of the triangulated touch points may result in multiple potential touch points having the same distance to a given detector. As another example, the calculated distance and distance for the same point as measured using shadow extension may not match exactly due to measurement or other inaccuracies.
- the distance as determined based on shadow extension may be measured along a line tangent to the touch point, rather than a line passing through the center of the touch point, which could lead to a slight variation in the estimated distance as compared to the distance determined from triangulated coordinates.
- distance metrics Metric1 and Metric2 can be calculated for use in identifying the actual touch points as follows:
- d 1 -d 4 are arguments determined as follows by subtracting calculated distances from the detector:
- the distance metrics are evaluated to identify the two actual points.
- the actual points are P 1 and P 3 if Metric1 ⁇ Metric2; otherwise, the actual points are P 2 and P 4 .
- the process can be repeated to calculate ranges Distance 1 through Distance 4 , Distance A , and Distance B relative to the other detector if necessary to resolve an ambiguous result and/or as an additional check to ensure accuracy.
- the actual touch points PA and PB as determined based on shadow extensions were each correlated to one of two potential touch points since the method assumes that two simultaneous shadows detected by the same detector each correspond to a unique touch point. Namely, actual point TA was correlated to one of potential touch points P 1 and P 3 , while actual touch point TB was correlated to one of potential touch points P 2 and P 4 . Variants of the distance metric could be used to accommodate different correlations or identities of the touch points.
- Method 300 may be a sub-process in a larger routine for touch detection.
- a conventional touch detection method may be modified to call an embodiment of method 300 to handle a multitouch scenario triggered by a detector identifying multiple simultaneous shadows or may be called in response to a triangulation calculation result identifying four potential touch points for a given sample interval.
- the coordinates as determined from triangulation or other technique(s) can be used in any suitable manner.
- user interface or other components that handle input provided via a touchscreen can be configured to support multitouch gestures specified by reference to two simultaneous touch points.
- touch points
- the same principles could be applied in another context, such as when a shadow is due to a “hover” with no actual contact with a touch surface.
- FIG. 10 is a block diagram illustrating an exemplary touch detection system 200 as interfaced to an exemplary computing device 401 to yield a touch screen system 400 .
- Computing device 401 may be functionally coupled to touch screen system 410 by hardwire and/or wireless connections.
- Computing device 401 may be any suitable computing device, including, but not limited to a processor-driven device such as a personal computer, a laptop computer, a handheld computer, a personal digital assistant (PDA), a digital and/or cellular telephone, a pager, a video game device, etc.
- PDA personal digital assistant
- processors can refer to any type of programmable logic device, including a microprocessor or any other type of similar device.
- Computing device 401 may include, for example, a processor 402 , a system memory 404 , and various system interface components 406 .
- the processor 402 , system memory 404 , a digital signal processing (DSP) unit 405 and system interface components 406 may be functionally connected via a system bus 408 .
- the system interface components 406 may enable the processor 402 to communicate with peripheral devices.
- a storage device interface 410 can provide an interface between the processor 402 and a storage device 341 (removable and/or non-removable), such as a disk drive.
- a network interface 412 may also be provided as an interface between the processor 402 and a network communications device (not shown), so that the computing device 401 can be connected to a network.
- a display screen interface 414 can provide an interface between the processor 402 and display device of the touch screen system.
- interface 414 may provide data in a suitable format for rendering by the display device over a DVI, VGA, or other suitable connection to a display positioned relative to touch detection system 200 so that touch area 204 corresponds to some or all of the display area.
- the display device may comprise a CRT, LCD, LED, or other suitable computer display, or may comprise a television, for example.
- the screen may be is bounded by edges 206 A, 206 B, and 206 D.
- a touch surface may correspond to the outer surface of the display or may correspond to the outer surface of a protective material positioned on the display.
- the touch surface may correspond to an area upon which the displayed image is projected from above or below the touch surface in some embodiments.
- One or more input/output (“I/O”) port interfaces 416 may be provided as an interface between the processor 402 and various input and/or output devices.
- the detection systems and illumination systems of touch detection system 200 may be connected to the computing device 401 and may provide input signals representing patterns of light detected by the detectors to the processor 402 via an input port interface 416 .
- the illumination systems and other components may be connected to the computing device 401 and may receive output signals from the processor 402 via an output port interface 416 .
- a number of program modules may be stored in the system memory 404 , any other computer-readable media associated with the storage device 411 (e.g., a hard disk drive), and/or any other data source accessible by computing device 401 .
- the program modules may include an operating system 417 .
- the program modules may also include an information display program module 419 comprising computer-executable instructions for displaying images or other information on a display screen.
- Other aspects of the exemplary embodiments of the invention may be embodied in a touch screen control program module 421 for controlling the primary and secondary illumination systems, detector assemblies, and/or for calculating touch locations, resolving multitouch scenarios (e.g., by implementing an embodiment of method 300 ), and discerning interaction states relative to the touch screen based on signals received from the detectors.
- a DSP unit is included for performing some or all of the functionality ascribed to the Touch Panel Control program module 421 .
- a DSP unit 405 may be configured to perform many types of calculations including filtering, data sampling, and triangulation and other calculations and to control the modulation and/or other characteristics of the illumination systems.
- the DSP unit 405 may include a series of scanning imagers, digital filters, and comparators implemented in software. The DSP unit 405 may therefore be programmed for calculating touch locations and discerning other interaction characteristics as known in the art.
- the processor 402 which may be controlled by the operating system 417 , can be configured to execute the computer-executable instructions of the various program modules. Methods in accordance with one or more aspects of the present subject matter may be carried out due to execution of such instructions. Furthermore, the images or other information displayed by the information display program module 419 may be stored in one or more information data files 423 , which may be stored on any computer readable medium associated with or accessible by the computing device 401 .
- the detectors are configured to detect the intensity of the energy beams reflected or otherwise scattered across the surface of the touch screen and should be sensitive enough to detect variations in such intensity.
- Information signals produced by the detector assemblies and/or other components of the touch screen display system may be used by the computing device 401 to determine the location of the touch relative to the touch area 431 .
- Computing device 401 may also determine the appropriate response to a touch on or near the screen.
- data from the detection system may be periodically processed by the computing device 401 to monitor the typical intensity level of the energy beams directed along the detection plane(s) when no touch is present. This allows the system to account for, and thereby reduce the effects of, changes in ambient light levels and other ambient conditions.
- the computing device 401 may optionally increase or decrease the intensity of the energy beams emitted by the primary and/or secondary illumination systems as needed. Subsequently, if a variation in the intensity of the energy beams is detected by the detection systems, computing device 401 can process this information to determine that a touch has occurred on or near the touch screen.
- the location of a touch relative to the touch screen may be determined, for example, by processing information received from each detection system and performing one or more well-known triangulation calculations plus resolving multitouch scenarios as noted above.
- the location of the area of decreased energy beam intensity relative to each detection system can be determined in relation to the coordinates of one or more pixels, or virtual pixels, of the display screen.
- the location of the area of increased or decreased energy beam intensity relative to each detector may then be triangulated, based on the geometry between the detection systems to determine the actual location of the touch relative to the touch screen. Any such calculations to determine touch location can include algorithms to compensation for discrepancies (e.g., lens distortions, ambient conditions, damage to or impediments on the touch screen or other touched surface, etc.), as applicable.
- discrepancies e.g., lens distortions, ambient conditions, damage to or impediments on the touch screen or other touched surface, etc.
- LEDs light emitting diodes
- IR infrared
- other portions of the EM spectrum or even other types of energy may be used as applicable with appropriate sources and detection systems.
- the touch area may feature a static image or no image at all.
- a detector assembly may comprise a light detector with a plurality of sources, such as one or more sources located on either side of the detector.
- a first pattern of light can be emitted by using the source(s) on both sides of the detector.
- the light emitted across the touch area can be changed to a second pattern of light by using the source(s) on one side of the detector, but not the other, to obtain changes in shadow length for range estimation.
- a computing device can include any suitable arrangement of components that provide a result conditioned on one or more inputs.
- Suitable computing devices include multipurpose microprocessor-based computer systems accessing stored software, but also application-specific integrated circuits and other programmable logic, and combinations thereof. Any suitable programming, scripting, or other type of language or combinations of languages may be used to implement the teachings contained herein in software.
- Embodiments of the methods disclosed herein may be executed by one or more suitable computing devices.
- Such system(s) may comprise one or more computing devices adapted to perform one or more embodiments of the methods disclosed herein.
- such devices may access one or more computer-readable media that embody computer-readable instructions which, when executed by at least one computer, cause the at least one computer to implement one or more embodiments of the methods of the present subject matter.
- the software may comprise one or more components, processes, and/or applications.
- the computing device(s) may comprise circuitry that renders the device(s) operative to implement one or more of the methods of the present subject matter.
- Any suitable computer-readable medium or media may be used to implement or practice the presently-disclosed subject matter, including, but not limited to, diskettes, drives, magnetic-based storage media, optical storage media, including disks (including CD-ROMS, DVD-ROMS, and variants thereof), flash, RAM, ROM, and other memory devices, and the like.
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Human Computer Interaction (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Position Input By Displaying (AREA)
- Length Measuring Devices By Optical Means (AREA)
- Measurement Of Optical Distance (AREA)
Abstract
An optical touch detection system may rely on triangulating points in a touch area based on the direction of shadows cast by an object interrupting light in the touch area. When two interruptions occur simultaneously, ghost points and true touch points triangulated from the shadows can be distinguished from one another without resort to additional light detectors. In some embodiments, a distance from a touch point to a single light detector can be determined or estimated based on a change in the length of a shadow detected by a light detector when multiple light sources are used. Based on the distance, the true touch points can be identified by comparing the distance as determined from shadow extension to a distance calculated from the triangulated location of the touch points.
Description
- This application claims priority to New Zealand Provisional Patent Application No. 565,808, filed on Feb. 11, 2008 and entitled OPTICAL TOUCHSCREEN RESOLVING MULTITOUCH, which is hereby incorporated by reference herein in its entirety.
- The present subject matter pertains to touch display systems that allow a user to interact with one or more processing devices by touching on or near a surface.
-
FIG. 1 illustrates an example of an optical/infrared-basedtouch detection system 100 that relies on detection of light traveling in optical paths that lie in one or more detection planes in an area 104 (“touch area” herein) above the touched surface.FIG. 2 features a perspective view of a portion ofsystem 100. For example, optical imaging for touch screens can use a combination of line-scan or area image cameras, digital signal processing, front or back illumination, and algorithms to determine a point or area of touch. In this example, twolight detectors view 110, with the field of view having anoptical center 112. - As shown in
FIG. 2 , in some systems, the light can be emitted across the surface of the touch screen by IR-LED emitters 114 aligned along the optical axis of the light detector to detect the existence or non existence of light reflected by a retro-reflective surface 107 along an edge oftouch area 104 via light returned through awindow 116. As shown inFIG. 1 at 108, the retroreflective surface along the edges oftouch area 104 returns light in the direction from which it originated. - As an alternative, the light may be emitted by components along one or more edges of
touch area 104 that direct light across the touch area and into light detectors 102 in the absence of interruption by an object. - As shown in the perspective view of
FIG. 2 , if an object 118 (a stylus in this example) is interrupting light in the detection plane, the object will cast ashadow 120 on the bezel (106A in this example) which is registered as a decrease in light retroreflected bysurface 107. In this particular example,light detector 102A would register the location ofshadow 120 to determine the direction of the shadow cast onborder 106A, whilelight detector 102B would register a shadow cast on the retroreflective surface onbezel portion -
FIG. 3 illustrates the geometry involved in the location of a touch point T relative totouch area 104 ofsystem 100. Based on the interruption in detected light, touch point T can be triangulated from the intersection of twolines Lines light detectors detector borders detector 102B. - The distance W between
light detectors lines - However, as shown at
FIG. 4 , problems can arise if two points are simultaneously touched, with “simultaneously” referring to touches that happen within a given time interval during which interruptions in light are evaluated. -
FIG. 4 shows two touch points T1 and T2 and four resultingshadows touch area 104. Although the centerlines are not illustrated in this example, Point T1 can be triangulated from respective centerlines ofshadows light detectors shadows light detectors shadows shadows - Objects and advantages of the present subject matter will be apparent to one of ordinary skill in the art upon careful review of the present disclosure and/or practice of one or more embodiments of the claimed subject matter.
- In accordance with one or more aspects of the present subject matter, ghost points and true touch points can be distinguished from one another without resort to additional light detectors. In some embodiments, a distance from a touch point to a single light detector can be determined or estimated based on a change in the length of a shadow detected by a light detector when multiple light sources and/or differing patterns of light are used. The distance can be used to validate one or more potential touch position coordinates.
- For example, the shadow cast due to interruption of a first pattern of light from a primary light source can be measured. Then, a second pattern of light can be used to illuminate the touch area. The change in length of the shadow will be proportional to the distance from the point of interruption (i.e., the touch point) to the light detector. The second pattern of light may be emitted from a secondary light source or may be emitted by changing how light is emitted from the primary light source. Distances from possible touch points as determined from triangulation can be considered alongside the distance determined from shadow extension to determine which possible touch points are “true” touch points and which ones are “ghost” touch points.
- A full and enabling disclosure including the best mode of practicing the appended claims and directed to one of ordinary skill in the art is set forth more particularly in the remainder of the specification. The specification makes reference to the following appended figures, in which use of like reference numerals in different features is intended to illustrate like or analogous components.
-
FIG. 1 is a block diagram illustrating an exemplary conventional touch screen system. -
FIG. 2 is a perspective view of the system ofFIG. 1 . -
FIG. 3 is a diagram illustrating the geometry involved in calculating touch points in a typical optical touch screen system. -
FIG. 4 is a diagram illustrating the occurrence of “ghost points” when multiple simultaneous touches occur in an optical touch screen system. -
FIG. 5 is a block diagram illustrating an exemplary touch detection system configured in accordance with one or more aspects of the present subject matter. -
FIGS. 6A and 6B illustrate changes in shadows cast by different touch points due to interruption of light from a secondary illumination source. -
FIGS. 7A and 7B illustrate the relationship between shadow extension length and light detector distance in closer detail. -
FIG. 8 is a flowchart showing an exemplary method of resolving a multitouch scenario. -
FIG. 9 is a diagram illustrating distances between potential touch points and estimated distances for actual touch points. -
FIG. 10 is a block diagram illustrating an exemplary touchscreen system. - Reference will now be made in detail to various and alternative exemplary embodiments and to the accompanying drawings. Each example is provided by way of explanation, and not as a limitation. It will be apparent to those skilled in the art that modifications and variations can be made without departing from the scope or spirit of the disclosure and claims. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield still further embodiments. Thus, it is intended that the present disclosure includes any modifications and variations as come within the scope of the appended claims and their equivalents.
-
FIG. 5 is a block diagram illustrating an exemplarytouch detection system 200 configured in accordance with one or more aspects of the present subject matter. In this example, twooptical units touch area 204 bounded on three sides by a retroreflective bezel 206 havingportions - The light detector of each optical unit 202 has a field of
view 210 with an optical center shown byray trace 212. The position of an interruption in the pattern of detected light relative to the optical center can be used to determine a direction of a shadow relative to the optical unit. As noted above, an interruption of light at a point intouch area 204 can correspond to a first shadow detected by one detector (e.g., the detector ofoptical unit 202A) and a second shadow detected by a second detector (e.g., the detector ofoptical unit 202B). By triangulating the shadows, the position of the interruption relative to toucharea 204 can be determined. -
FIG. 5 also illustrates asecondary illumination system 208.Secondary illumination system 208 comprises one or more sources of light positioned a known distance from the detector ofoptical unit 202B (and the detector ofoptical unit 202A). As illustrated byray trace 213,secondary illumination system 208 emits light off-center relative to the optical center of the detector of eitheroptical unit - However, it is not necessary for the primary illumination source to be aligned with the optical center in all embodiments. Rather, light emitted across the touch area can be changed in any suitable manner so as to change shadow length. For example, both the primary and secondary illumination systems could be off-center relative to a detector. As another example, the secondary illumination may be on-center while the primary illumination is off-center.
- Distance estimates based on changes in shadow length can be used to resolve or confirm multitouch scenarios.
FIGS. 6A and 6B illustrate changes in shadows cast by a touch point T due to interruption of light from a primary illumination source associated withoptical unit 202A andsecondary illumination source 208. InFIG. 6A , an interruption due to touch point T casts a shadowS1 having edges centerline 218 of shadow S1. -
FIG. 6B shows that the illumination intouch area 204 has changed. Namely, light fromsecondary source 208 is emitted as represented bydotted lines 220. The detector ofoptical unit 202A images the resulting shadow cast due to the interruption at touch point T. Sincesecondary illumination source 208 is off-center relative to the detector ofoptical unit 202A, a different shadow is cast. Specifically, in this example, a larger shadow is cast, with the difference in shadow length along the edge of touch are 204 illustrated at dS. This lengthening effect is due to the fact that the shadow from the field of view ofdetector 202A hasedges Centerline 218 of the original shadow S1 is shown for reference. -
FIGS. 7A and 7B illustrate the geometry of the shadow length extension in closer detail for a case in which point T is relatively close to the detector ofoptical unit 202A (shown inFIG. 7A ) and a case in which point T is farther from the detector ofoptical unit 202A (shown inFIG. 7B ). - In each of these examples, illumination from
secondary illumination source 208 is represented as ray traces 220 and 221 along withshadow edges detector 202A. Original shadow edge 216 (i.e. the shadow edge when light from the primary illumination system is interrupted) is shown for reference, along with the boundaries of S1 and shadow extension dS. - Each of
FIGS. 7A and 7B include an inset illustrating distances dA (the distance betweensecondary illumination source 208 and the detector ofoptical unit 202A); distance dY (the length of one side of touch area 204), shadow extension length dS, and a length dX along the side oftouch area 204 opposite length dA (but not necessarily equal to dA). An angle φ is shown representing the angle between the top side oftouch area 204 andoriginal shadow edge 216; this angle may be derived using a ray trace of the original shadow boundaries. An angle {circumflex over (-)} is also illustrated as formed from the intersection betweenshadow edge 216 andray trace 221. - The intersection between
shadow edge 216 andray trace 221 can be treated as a proxy for the position of touch point T. Thus, portion rA ofray trace 216 can be treated as an estimate of the distance from the detector ofoptical unit 202A to touch point T.FIGS. 7A and 7B show that as the distance rA from T to optical unit 212A varies, the length dS varies, with dS being larger if T is closer to the detector in this example. Different patterns of light may result in dS becoming shorter as T moves closer to the detector, so the use of shadow “lengthening” in this example is not meant to be limiting. - Ray traces 221 and 216 form two sides of an upper triangle and a lower triangle. The third side of the upper triangle has a length equal to dA and the third side of the lower triangle has a length equal to dS. One side of the upper triangle has a length rA, while one side of the lower triangle has a length rB.
- The upper and lower triangles formed by
rays -
rA/rB=dA/dS - Because the distance dA from the
secondary illumination source 208 to the detector ofoptical unit 202B is known, then the distance RA from point P to optical unit 212B can be calculated or estimated as: -
rA=rB*(dA/dS) - To solve for rA, rB can be expressed as a function of rA since the total length (rA+rB) from
detector 202B to the bottom edge oftouch area 204 is easily computed as the hypotenuse of a third (right) triangle formed by ray trace 216 (whose total length is RA+RB), vertical side Y (whose length is dY) of touch area 204 (which is known), and horizontal side having a length dX: -
(rA+rB)=dY/sin Φ -
rB=(dY/sin Φ)−rA - Following this, then:
-
rB=rA*(dS/dA) -
rB=(dY/sin Φ)−RA -
rA*(dS/dA)=(dY/sin Φ)−rA -
rA*(1+dS/dA)=(dY/sin Φ) - Gives an estimation (rA) of the distance (or range) from the actual touch point to the detector:
-
rA=(dY/sin Φ)/(1+dS/dA) - The distance rA is referred to as an “estimation” because, in practice, the accuracy of the shadow length may vary with the distance of the interruption from the detector. This phenomenon is related to the variations in detection accuracy that can occur based on relative position in the touch area as is known in the art. Additionally, in this example, the intersection between
ray -
FIG. 8 is a flowchart showing anexemplary method 300 for resolving a multitouch scenario based on a distance determined using a secondary illumination system.FIG. 9 is a diagram illustrating distances between potential touch points and estimated ranges for actual touch points and will be discussed alongsideFIG. 9 . - As discussed below, distances estimated from changes in shadow size can validate potential touch coordinates, which in this example are calculated from triangulating shadows. However, this is for purposes of example only, and in embodiments one or more potential touch coordinates could be identified in any other suitable fashion and then validated using a technique based on shadow extension.
- At
block 302, a distance from the detector of to each of the four potential touch points is calculated. Four potential touch points can be identified based on the directions of shadows cast by simultaneous interruptions in light traveling across the touch area. For example, a first pattern of light may be used for determining the four points from triangulation. -
FIG. 9 shows an example of fourshadows having centerlines centerline 901 results from an interruption of light at a first point TA in the touch area and is detected using a first detector (i.e. the detector ofoptical unit 202A). A second shadow SA-2 having acenterline 902 also results from the interruption at point PA and is detected using the detector ofoptical unit 202B. A third shadow SB-1 having acenterline 903 and a fourth shadow SB-2 having acenterline 904 are created by an interruption at point TB simultaneous to the interruption at point TA and are detected using the first and second detectors, respectively. - As noted above, two interruptions may be considered “simultaneous” if the interruptions occur within a given time window for light detection/touch location. For example, the interruptions may occur the same sampling interval or over multiple sampling intervals considered together. The interruptions may be caused by different objects (e.g., two fingers, a finger and a stylus, etc.) or different portions of the same object that intrude into the detection area at different locations, for example.
- The centerlines intersect at four points corresponding to potential touch points P1, P2, P3, and P4.
FIG. 9 also illustrates actual touch points “TA” and “TB” as solid circles. The relative position of the actual touch points to the potential touch points is not known to the touch detection system, however. The actual touch points may of course coincide with potential touch points but are shown inFIG. 9 as separate from potential touch points for purposes of illustratingexemplary method 300, which can be used to determine which triangulated touch points actually correspond to the interruptions in the touch area. -
Block 302 inFIG. 8 represents calculating a distance from one of the detectors to each of the four potential touch points P1-P4. This distance (DistanceN) can be determined, for example, using the triangulated coordinates (X,Y) for each point (PN) using the following expression: -
DISTANCEN=√{square root over (X N 2 +Y N 2)} -
Block 304 ofFIG. 8 represents calculating an estimated distance from the detector to each of the two touch points based on identifying a shadow extension. This can be determined based on comparing the patterns of light detected by a single detector under a first illumination condition (e.g., a first pattern of light, such as a pattern of light from the detector's primary illumination source) and then changing the illumination to a second pattern of light (e.g., by illuminating using a secondary illumination system while the primary illumination is not used or changing the pattern of light emitted from the primary illumination system). - To determine a distance (DistanceA) from point TA to the detector of
optical unit 202A inFIG. 9 , a change in length of shadow SA-1 could be determined. To determine a distance (DistanceB) from point TB to the detector, a change in length of shadow SB-1 could be determined. A distance from each point to the detector can be determined using the expression solved above for rA based on the length of the respective shadow extensions as compared to the distance between the detector and the light source used to emit the second pattern of light. - Once the distance from each actual touch point to the detector is known or estimated, the actual ranges can be considered alongside the calculated ranges for the potential touch points P1-P4 to determine which touch points are actual touch points.
- As shown at
block 306 ofFIG. 8 , a distance metric can be calculated for use in identifying the “actual” touch points. A distance metric is used in some embodiments since a direct comparison between the calculated ranges and the ranges as determined by shadow length changes may lead to ambiguous results. For example, the coordinates of the triangulated touch points may result in multiple potential touch points having the same distance to a given detector. As another example, the calculated distance and distance for the same point as measured using shadow extension may not match exactly due to measurement or other inaccuracies. For instance, in some embodiments, the distance as determined based on shadow extension may be measured along a line tangent to the touch point, rather than a line passing through the center of the touch point, which could lead to a slight variation in the estimated distance as compared to the distance determined from triangulated coordinates. - In some embodiments, distance metrics Metric1 and Metric2 can be calculated for use in identifying the actual touch points as follows:
-
Metric1=d1+d3 -
Metric2=d2+d4 - In this example, d1-d4 are arguments determined as follows by subtracting calculated distances from the detector:
-
d1=Distance1−DistanceA -
d2=DistanceB−Distance2 -
d3=Distance3−DistanceB -
d4=Distance4−DistanceA - At
block 308, the distance metrics are evaluated to identify the two actual points. In this example, the actual points are P1 and P3 if Metric1<Metric2; otherwise, the actual points are P2 and P4. - The example above was carried out with reference to ranges from one of the detectors. In some embodiments, the process can be repeated to calculate ranges Distance1 through Distance4, DistanceA, and DistanceB relative to the other detector if necessary to resolve an ambiguous result and/or as an additional check to ensure accuracy.
- In the example above, the actual touch points PA and PB as determined based on shadow extensions were each correlated to one of two potential touch points since the method assumes that two simultaneous shadows detected by the same detector each correspond to a unique touch point. Namely, actual point TA was correlated to one of potential touch points P1 and P3, while actual touch point TB was correlated to one of potential touch points P2 and P4. Variants of the distance metric could be used to accommodate different correlations or identities of the touch points.
-
Method 300 may be a sub-process in a larger routine for touch detection. For example, a conventional touch detection method may be modified to call an embodiment ofmethod 300 to handle a multitouch scenario triggered by a detector identifying multiple simultaneous shadows or may be called in response to a triangulation calculation result identifying four potential touch points for a given sample interval. Once the “actual” points have been identified, the coordinates as determined from triangulation or other technique(s) can be used in any suitable manner. - For example, user interface or other components that handle input provided via a touchscreen can be configured to support multitouch gestures specified by reference to two simultaneous touch points. Although the examples herein referred to “touch” points, the same principles could be applied in another context, such as when a shadow is due to a “hover” with no actual contact with a touch surface.
-
FIG. 10 is a block diagram illustrating an exemplarytouch detection system 200 as interfaced to anexemplary computing device 401 to yield atouch screen system 400.Computing device 401 may be functionally coupled totouch screen system 410 by hardwire and/or wireless connections.Computing device 401 may be any suitable computing device, including, but not limited to a processor-driven device such as a personal computer, a laptop computer, a handheld computer, a personal digital assistant (PDA), a digital and/or cellular telephone, a pager, a video game device, etc. These and other types of processor-driven devices will be apparent to those of skill in the art. As used in this discussion, the term “processor” can refer to any type of programmable logic device, including a microprocessor or any other type of similar device. -
Computing device 401 may include, for example, aprocessor 402, asystem memory 404, and varioussystem interface components 406. Theprocessor 402,system memory 404, a digital signal processing (DSP)unit 405 andsystem interface components 406 may be functionally connected via a system bus 408. Thesystem interface components 406 may enable theprocessor 402 to communicate with peripheral devices. For example, astorage device interface 410 can provide an interface between theprocessor 402 and a storage device 341 (removable and/or non-removable), such as a disk drive. Anetwork interface 412 may also be provided as an interface between theprocessor 402 and a network communications device (not shown), so that thecomputing device 401 can be connected to a network. - A
display screen interface 414 can provide an interface between theprocessor 402 and display device of the touch screen system. For instance,interface 414 may provide data in a suitable format for rendering by the display device over a DVI, VGA, or other suitable connection to a display positioned relative to touchdetection system 200 so thattouch area 204 corresponds to some or all of the display area. The display device may comprise a CRT, LCD, LED, or other suitable computer display, or may comprise a television, for example. - The screen may be is bounded by
edges - One or more input/output (“I/O”) port interfaces 416 may be provided as an interface between the
processor 402 and various input and/or output devices. For example, the detection systems and illumination systems oftouch detection system 200 may be connected to thecomputing device 401 and may provide input signals representing patterns of light detected by the detectors to theprocessor 402 via aninput port interface 416. Similarly, the illumination systems and other components may be connected to thecomputing device 401 and may receive output signals from theprocessor 402 via anoutput port interface 416. - A number of program modules may be stored in the
system memory 404, any other computer-readable media associated with the storage device 411 (e.g., a hard disk drive), and/or any other data source accessible bycomputing device 401. The program modules may include anoperating system 417. The program modules may also include an information display program module 419 comprising computer-executable instructions for displaying images or other information on a display screen. Other aspects of the exemplary embodiments of the invention may be embodied in a touch screencontrol program module 421 for controlling the primary and secondary illumination systems, detector assemblies, and/or for calculating touch locations, resolving multitouch scenarios (e.g., by implementing an embodiment of method 300), and discerning interaction states relative to the touch screen based on signals received from the detectors. - In some embodiments, a DSP unit is included for performing some or all of the functionality ascribed to the Touch Panel
Control program module 421. As is known in the art, aDSP unit 405 may be configured to perform many types of calculations including filtering, data sampling, and triangulation and other calculations and to control the modulation and/or other characteristics of the illumination systems. TheDSP unit 405 may include a series of scanning imagers, digital filters, and comparators implemented in software. TheDSP unit 405 may therefore be programmed for calculating touch locations and discerning other interaction characteristics as known in the art. - The
processor 402, which may be controlled by theoperating system 417, can be configured to execute the computer-executable instructions of the various program modules. Methods in accordance with one or more aspects of the present subject matter may be carried out due to execution of such instructions. Furthermore, the images or other information displayed by the information display program module 419 may be stored in one or more information data files 423, which may be stored on any computer readable medium associated with or accessible by thecomputing device 401. - When a user touches on or near the touch screen, a variation will occur in the intensity of the energy beams that are directed across the surface of the touch screen in one or more detection planes. The detectors are configured to detect the intensity of the energy beams reflected or otherwise scattered across the surface of the touch screen and should be sensitive enough to detect variations in such intensity. Information signals produced by the detector assemblies and/or other components of the touch screen display system may be used by the
computing device 401 to determine the location of the touch relative to the touch area 431.Computing device 401 may also determine the appropriate response to a touch on or near the screen. - In accordance with some implementations, data from the detection system may be periodically processed by the
computing device 401 to monitor the typical intensity level of the energy beams directed along the detection plane(s) when no touch is present. This allows the system to account for, and thereby reduce the effects of, changes in ambient light levels and other ambient conditions. Thecomputing device 401 may optionally increase or decrease the intensity of the energy beams emitted by the primary and/or secondary illumination systems as needed. Subsequently, if a variation in the intensity of the energy beams is detected by the detection systems,computing device 401 can process this information to determine that a touch has occurred on or near the touch screen. - The location of a touch relative to the touch screen may be determined, for example, by processing information received from each detection system and performing one or more well-known triangulation calculations plus resolving multitouch scenarios as noted above. The location of the area of decreased energy beam intensity relative to each detection system can be determined in relation to the coordinates of one or more pixels, or virtual pixels, of the display screen. The location of the area of increased or decreased energy beam intensity relative to each detector may then be triangulated, based on the geometry between the detection systems to determine the actual location of the touch relative to the touch screen. Any such calculations to determine touch location can include algorithms to compensation for discrepancies (e.g., lens distortions, ambient conditions, damage to or impediments on the touch screen or other touched surface, etc.), as applicable.
- The above examples referred to various illumination sources and it should be understood that any suitable radiation source can be used. For instance, light emitting diodes (LEDs) may be used to generate infrared (IR) radiation that is directed over one or more optical paths in the detection plane. However, other portions of the EM spectrum or even other types of energy may be used as applicable with appropriate sources and detection systems.
- Several of the above examples were presented in the context of a touch-enabled display. However, it will be understood that the principles disclosed herein could be applied even in the absence of a display screen when the position of an object relative to an area is to be tracked. For example, the touch area may feature a static image or no image at all.
- In several examples, secondary illumination systems are shown as separate from the primary illumination system. In some embodiments, the “primary illumination system” and “secondary illumination system” may use some or all of the same components. For example, a detector assembly may comprise a light detector with a plurality of sources, such as one or more sources located on either side of the detector. A first pattern of light can be emitted by using the source(s) on both sides of the detector. The light emitted across the touch area can be changed to a second pattern of light by using the source(s) on one side of the detector, but not the other, to obtain changes in shadow length for range estimation.
- The various systems discussed herein are not limited to any particular hardware architecture or configuration. As was noted above, a computing device can include any suitable arrangement of components that provide a result conditioned on one or more inputs. Suitable computing devices include multipurpose microprocessor-based computer systems accessing stored software, but also application-specific integrated circuits and other programmable logic, and combinations thereof. Any suitable programming, scripting, or other type of language or combinations of languages may be used to implement the teachings contained herein in software.
- Embodiments of the methods disclosed herein may be executed by one or more suitable computing devices. Such system(s) may comprise one or more computing devices adapted to perform one or more embodiments of the methods disclosed herein. As noted above, such devices may access one or more computer-readable media that embody computer-readable instructions which, when executed by at least one computer, cause the at least one computer to implement one or more embodiments of the methods of the present subject matter. When software is utilized, the software may comprise one or more components, processes, and/or applications. Additionally or alternatively to software, the computing device(s) may comprise circuitry that renders the device(s) operative to implement one or more of the methods of the present subject matter.
- Any suitable computer-readable medium or media may be used to implement or practice the presently-disclosed subject matter, including, but not limited to, diskettes, drives, magnetic-based storage media, optical storage media, including disks (including CD-ROMS, DVD-ROMS, and variants thereof), flash, RAM, ROM, and other memory devices, and the like.
- While the present subject matter has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, it should be understood that the present disclosure has been presented for purposes of example rather than limitation, and does not preclude inclusion of such modifications, variations and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art
Claims (19)
1. A method of determining multiple touch points, the method comprising:
detecting a first shadow resulting from an interruption of light at a first point in a touch area using a first detector;
changing light traveling in the touch area so that a length of at least one shadow changes;
based on the length of the shadow as changed, calculating a distance from the first point to the first detector; and
using the distance as calculated to validate a potential touch position coordinate for the first point.
2. The method of determining multiple touch points as set forth in claim 1 , further comprising:
detecting a second shadow resulting from the interruption of light at the first point in the touch area using a second detector;
detecting a third shadow resulting from an interruption of light at a second point in the touch area using the first detector, the interruption at the second point occurring during a time interval during which the first and second shadows are detected;
detecting a fourth shadow resulting from the interruption of light at the second point in the touch area using the second detector;
determining four potential touch position coordinates based on the directions of the first and third shadows relative to the first detector and the directions of the second and fourth shadows relative to the second detector;
wherein whilst using the distance as calculated to validate a potential position coordinate for the first point, two actual touch positions are determined from the four potential touch positions.
3. The method set forth in claim 2 , wherein changing light traveling in the touch area comprises emitting light from a secondary illumination source positioned a distance from the detector.
4. The method set forth in claim 3 ,
wherein prior to changing light traveling in the touch area, light is emitted from a primary illumination source; and
wherein while light is emitted from the secondary illumination source, light is not illuminated from the primary illumination source.
5. The method set forth in claim 3 , wherein the primary and secondary illumination source are positioned on opposite sides of the detector.
6. The method set forth in claim 3 , wherein determining a distance from the first point to the first detector is based on a function of a change in length of the shadow as related to the distance between the secondary illumination source and the first detector.
7. The method set forth in claim 2 , wherein determining four potential touch position coordinates based on the directions of the first and third shadows relative to the first detector and the directions of the second and fourth shadows comprises triangulating the four potential touch positions coordinates from intersections between ray traces associated with the shadows.
8. A touch detection system, comprising:
a retroreflector positioned along at least one edge of a touch surface in a touch area;
a light detection system having an optical center and positioned to image the retroreflector;
an illumination system configured to emit light across the touch surface so that at least some of the light from the illumination system is retroreflected to the light detection system in the absence of an object in the touch area; and
a computing system interfaced with the light detection system and the illumination system, the computing system configured to determine a distance from the light detection system to a point at which light in the touch area has been interrupted based on: (i) a first pattern of detected light indicating an interruption in a first pattern of light from the illumination system due to an object at the point and (ii) a second pattern of detected light representing an interruption in a second pattern of light from the illumination system due to the object at the point.
9. The touch detection system set forth in claim 8 , wherein the first pattern of light is emitted from a primary illumination source of the illumination system and the second pattern of light is emitted from a secondary illumination source of the illumination system, the secondary illumination source located a known distance from a detector of the light detection system.
10. The touch detection system set forth in claim 9 , wherein the first and second pattern of detected light are evaluated to determine a change in shadow length, and
wherein the distance to the point at which light in the touch area has been interrupted is determined based on a function of the change in shadow length as related to the distance between the secondary illumination source and the light detection system.
11. The touch detection system set forth in claim 8 ,
wherein the light detection system and the illumination system are incorporated into a single optical unit and the system comprises two of the optical units, each optical unit positioned remote from the retroreflector and each other.
12. The touch detection system set forth in claim 11 , wherein the light detection system comprises a light detector and the illumination system comprises a plurality of light sources, the light sources positioned on opposite sides of the light detector.
13. The touch detection system set forth in claim 11 , wherein the computing system is further configured to:
(i) determine four potential touch points based on triangulation from shadows detected by the optical unit based on interruptions in light from the primary illumination systems,
(ii) determine two estimated distances, each estimated distance corresponding to one of two simultaneous interruptions, and
(iii) identify two of the potential touch points as actual touch points based on the estimated distances.
14. The touch detection system set forth in claim 13 , wherein the actual touch points are identified based on a distance metric determined using the estimated distances as determined from changes in shadow length and calculated distances for each potential touch point calculated based on triangulation.
15. A computer readable medium embodying program code executable by a computer system, the program code comprising:
program code for accessing detection data from two light detectors and identifying two shadows detected by each detector, the shadows due to interruptions in a first pattern of light traveling in a touch area;
program code for directing a light source to illuminate the touch area using a second pattern of light;
program code for accessing detection data from one light detector and identifying a change in the size of a shadow, the change in size occurring when the second pattern of light illuminates the touch area; and
program code for determining a distance from a point in the touch area to the detector based on the change in size of the shadow.
16. The computer-readable medium set forth in claim 15 , further comprising:
program code for identifying a plurality of potential touch points from the detected shadows; and
program code for identifying a subset of the potential touch points as actual touch points based on the distance determined from a change in size of the shadow.
17. The computer-readable medium set forth in claim 16 , wherein the program code for identifying a plurality of potential touch points from the detected shadows identifies the potential touch points through triangulation.
18. The computer-readable medium set forth in claim 15 , further comprising:
program code for directing a light source to illuminate the touch area using the first pattern of light,
wherein the first and second patterns of light are emitted at different times.
19. The computer-readable medium set forth in claim 18 , wherein the program code for directing the light source to illuminate the touch area using first and second patterns of light directs a plurality of light sources included in a single optical unit to emit light so that, when the second pattern of light is to be used, at least one light source in the optical unit is not illuminated.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/613,956 US20100045629A1 (en) | 2008-02-11 | 2009-11-06 | Systems For Resolving Touch Points for Optical Touchscreens |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NZ565808 | 2008-02-11 | ||
NZ56580808 | 2008-02-11 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/613,956 Continuation US20100045629A1 (en) | 2008-02-11 | 2009-11-06 | Systems For Resolving Touch Points for Optical Touchscreens |
Publications (1)
Publication Number | Publication Date |
---|---|
US20090219256A1 true US20090219256A1 (en) | 2009-09-03 |
Family
ID=40786585
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/368,372 Abandoned US20090219256A1 (en) | 2008-02-11 | 2009-02-10 | Systems and Methods for Resolving Multitouch Scenarios for Optical Touchscreens |
US12/613,956 Abandoned US20100045629A1 (en) | 2008-02-11 | 2009-11-06 | Systems For Resolving Touch Points for Optical Touchscreens |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/613,956 Abandoned US20100045629A1 (en) | 2008-02-11 | 2009-11-06 | Systems For Resolving Touch Points for Optical Touchscreens |
Country Status (5)
Country | Link |
---|---|
US (2) | US20090219256A1 (en) |
EP (1) | EP2250546A2 (en) |
KR (1) | KR20100121512A (en) |
CN (1) | CN101971129A (en) |
WO (1) | WO2009102681A2 (en) |
Cited By (64)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100045629A1 (en) * | 2008-02-11 | 2010-02-25 | Next Holdings Limited | Systems For Resolving Touch Points for Optical Touchscreens |
US20100090986A1 (en) * | 2008-10-15 | 2010-04-15 | Yanfeng Wang | Multi-touch positioning method and multi-touch screen |
US20100207912A1 (en) * | 2009-02-13 | 2010-08-19 | Arima Lasers Corp. | Detection module and an optical detection system comprising the same |
US20100245292A1 (en) * | 2009-03-31 | 2010-09-30 | Arima Lasers Corp. | Optical detection apparatus and method |
US20100302207A1 (en) * | 2009-05-27 | 2010-12-02 | Lan-Rong Dung | Optical Touch Control Method and Apparatus Thereof |
US20110050649A1 (en) * | 2009-09-01 | 2011-03-03 | John David Newton | Determining the Location of Touch Points in a Position Detection System |
US20110074735A1 (en) * | 2008-06-23 | 2011-03-31 | Flatfrog Laboratories Ab | Detecting the locations of a plurality of objects on a touch surface |
US20110074734A1 (en) * | 2008-06-23 | 2011-03-31 | Ola Wassvik | Detecting the location of an object on a touch surface |
US20110090176A1 (en) * | 2008-06-23 | 2011-04-21 | Flatfrog Laboratories Ab | Determining the location of one or more objects on a touch surface |
US20110109565A1 (en) * | 2010-02-04 | 2011-05-12 | Hong Kong Applied Science And Technology Research Institute Co. Ltd. | Cordinate locating method, coordinate locating device, and display apparatus comprising the coordinate locating device |
US20110115746A1 (en) * | 2009-11-16 | 2011-05-19 | Smart Technologies Inc. | Method for determining the location of a pointer in a pointer input region, and interactive input system executing the method |
US20110116105A1 (en) * | 2010-02-04 | 2011-05-19 | Hong Kong Applied Science and Technology Research Institute Company Limited | Coordinate locating method and apparatus |
US20110116104A1 (en) * | 2009-11-16 | 2011-05-19 | Pixart Imaging Inc. | Locating Method of Optical Touch Device and Optical Touch Device |
US20110163996A1 (en) * | 2008-06-23 | 2011-07-07 | Ola Wassvik | Determining the location of one or more objects on a touth surface |
US20110298708A1 (en) * | 2010-06-07 | 2011-12-08 | Microsoft Corporation | Virtual Touch Interface |
US20110316813A1 (en) * | 2010-06-23 | 2011-12-29 | Ren-Hau Gu | Optical touch display |
US8115753B2 (en) | 2007-04-11 | 2012-02-14 | Next Holdings Limited | Touch screen system with hover and click input methods |
US20120050224A1 (en) * | 2010-08-24 | 2012-03-01 | Quanta Computer Inc. | Optical touch system and method |
US8149221B2 (en) | 2004-05-07 | 2012-04-03 | Next Holdings Limited | Touch panel display system with illumination and detection provided from a single edge |
US20120098795A1 (en) * | 2010-10-20 | 2012-04-26 | Pixart Imaging Inc. | Optical touch screen system and sensing method for the same |
CN102479002A (en) * | 2010-11-30 | 2012-05-30 | 原相科技股份有限公司 | Optical touch control system and sensing method thereof |
US20120206410A1 (en) * | 2011-02-15 | 2012-08-16 | Hsun-Hao Chang | Method and system for generating calibration information for an optical imaging touch display device |
US20120212458A1 (en) * | 2008-08-07 | 2012-08-23 | Rapt Ip Limited | Detecting Multitouch Events in an Optical Touch-Sensitive Device by Combining Beam Information |
US20120223916A1 (en) * | 2009-11-17 | 2012-09-06 | Dax Kukulj | Apparatus and method for receiving a touch input |
US8289299B2 (en) | 2003-02-14 | 2012-10-16 | Next Holdings Limited | Touch screen signal processing |
US8338725B2 (en) | 2010-04-29 | 2012-12-25 | Au Optronics Corporation | Camera based touch system |
JP2013025710A (en) * | 2011-07-25 | 2013-02-04 | Canon Inc | Coordinate input device and method for controlling the same, and program |
US8384693B2 (en) | 2007-08-30 | 2013-02-26 | Next Holdings Limited | Low profile touch panel systems |
US8405636B2 (en) | 2008-01-07 | 2013-03-26 | Next Holdings Limited | Optical position sensing system and optical position sensor assembly |
US8432377B2 (en) | 2007-08-30 | 2013-04-30 | Next Holdings Limited | Optical touchscreen with improved illumination |
US8456447B2 (en) | 2003-02-14 | 2013-06-04 | Next Holdings Limited | Touch screen signal processing |
US8508508B2 (en) | 2003-02-14 | 2013-08-13 | Next Holdings Limited | Touch screen signal processing with single-point calibration |
US20130234993A1 (en) * | 2010-11-26 | 2013-09-12 | Haibing Zhang | Infrared touch screen multi-point recognizing method and infrared touch screen |
US20140015805A1 (en) * | 2012-01-04 | 2014-01-16 | Nexio Co., Ltd. | Infrared rays touch screen apparatus using array of infrared rays elements in two opposite sides |
US8704802B2 (en) * | 2010-10-12 | 2014-04-22 | Au Optronics Corporation | Touch display device |
US20140125588A1 (en) * | 2012-11-02 | 2014-05-08 | Wistron Corp. | Electronic device and operation method thereof |
US20140253512A1 (en) * | 2013-03-11 | 2014-09-11 | Hitachi Maxell, Ltd. | Manipulation detection apparatus, manipulation detection method, and projector |
US8971572B1 (en) | 2011-08-12 | 2015-03-03 | The Research Foundation For The State University Of New York | Hand pointing estimation for human computer interaction |
US9092092B2 (en) | 2008-08-07 | 2015-07-28 | Rapt Ip Limited | Detecting multitouch events in an optical touch-sensitive device using touch event templates |
US9395848B2 (en) * | 2014-04-30 | 2016-07-19 | Quanta Computer Inc. | Optical touch control systems and methods thereof |
US9874978B2 (en) | 2013-07-12 | 2018-01-23 | Flatfrog Laboratories Ab | Partial detect mode |
US10019113B2 (en) | 2013-04-11 | 2018-07-10 | Flatfrog Laboratories Ab | Tomographic processing for touch detection |
US10126882B2 (en) | 2014-01-16 | 2018-11-13 | Flatfrog Laboratories Ab | TIR-based optical touch systems of projection-type |
US10146376B2 (en) | 2014-01-16 | 2018-12-04 | Flatfrog Laboratories Ab | Light coupling in TIR-based optical touch systems |
US10161886B2 (en) | 2014-06-27 | 2018-12-25 | Flatfrog Laboratories Ab | Detection of surface contamination |
US10168835B2 (en) | 2012-05-23 | 2019-01-01 | Flatfrog Laboratories Ab | Spatial resolution in touch displays |
US10282035B2 (en) | 2016-12-07 | 2019-05-07 | Flatfrog Laboratories Ab | Touch device |
US10318074B2 (en) | 2015-01-30 | 2019-06-11 | Flatfrog Laboratories Ab | Touch-sensing OLED display with tilted emitters |
US10401546B2 (en) | 2015-03-02 | 2019-09-03 | Flatfrog Laboratories Ab | Optical component for light coupling |
US10437389B2 (en) | 2017-03-28 | 2019-10-08 | Flatfrog Laboratories Ab | Touch sensing apparatus and method for assembly |
US10474249B2 (en) | 2008-12-05 | 2019-11-12 | Flatfrog Laboratories Ab | Touch sensing apparatus and method of operating the same |
US10481737B2 (en) | 2017-03-22 | 2019-11-19 | Flatfrog Laboratories Ab | Pen differentiation for touch display |
US10496227B2 (en) | 2015-02-09 | 2019-12-03 | Flatfrog Laboratories Ab | Optical touch system comprising means for projecting and detecting light beams above and inside a transmissive panel |
US10761657B2 (en) | 2016-11-24 | 2020-09-01 | Flatfrog Laboratories Ab | Automatic optimisation of touch signal |
US11182023B2 (en) | 2015-01-28 | 2021-11-23 | Flatfrog Laboratories Ab | Dynamic touch quarantine frames |
US11256371B2 (en) | 2017-09-01 | 2022-02-22 | Flatfrog Laboratories Ab | Optical component |
US11301089B2 (en) | 2015-12-09 | 2022-04-12 | Flatfrog Laboratories Ab | Stylus identification |
US11474644B2 (en) | 2017-02-06 | 2022-10-18 | Flatfrog Laboratories Ab | Optical coupling in touch-sensing systems |
US11567610B2 (en) | 2018-03-05 | 2023-01-31 | Flatfrog Laboratories Ab | Detection line broadening |
US11893189B2 (en) | 2020-02-10 | 2024-02-06 | Flatfrog Laboratories Ab | Touch-sensing apparatus |
US11943563B2 (en) | 2019-01-25 | 2024-03-26 | FlatFrog Laboratories, AB | Videoconferencing terminal and method of operating the same |
US12055969B2 (en) | 2018-10-20 | 2024-08-06 | Flatfrog Laboratories Ab | Frame for a touch-sensitive device and tool therefor |
US12056316B2 (en) | 2019-11-25 | 2024-08-06 | Flatfrog Laboratories Ab | Touch-sensing apparatus |
US12086362B2 (en) | 2017-09-01 | 2024-09-10 | Flatfrog Laboratories Ab | Optical component |
Families Citing this family (35)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090213093A1 (en) * | 2008-01-07 | 2009-08-27 | Next Holdings Limited | Optical position sensor using retroreflection |
US20090207144A1 (en) * | 2008-01-07 | 2009-08-20 | Next Holdings Limited | Position Sensing System With Edge Positioning Enhancement |
KR20110066198A (en) * | 2008-10-02 | 2011-06-16 | 넥스트 홀딩즈 리미티드 | Stereo optical sensors for resolving multi-touch in a touch detection system |
JP5335923B2 (en) * | 2009-08-25 | 2013-11-06 | シャープ株式会社 | Position recognition sensor, electronic device, and display device |
TWI410841B (en) * | 2009-09-24 | 2013-10-01 | Acer Inc | Optical touch system and its method |
US8928608B2 (en) * | 2009-09-30 | 2015-01-06 | Beijing Irtouch Systems Co., Ltd | Touch screen, touch system and method for positioning a touch object in touch system |
JP5265778B2 (en) * | 2009-10-07 | 2013-08-14 | シャープ株式会社 | Touch panel |
RU2012118595A (en) * | 2009-10-19 | 2013-11-27 | ФлэтФрог Лэборэторис АБ | RETRIEVING TOUCH DATA REPRESENTING ONE OR SEVERAL ITEMS ON A TOUCH SURFACE |
US9430079B2 (en) | 2009-10-19 | 2016-08-30 | Flatfrog Laboratories Ab | Determining touch data for one or more objects on a touch surface |
EP2495637A4 (en) * | 2009-10-26 | 2015-06-17 | Sharp Kk | Position detection system, display panel, and display device |
US20110199387A1 (en) * | 2009-11-24 | 2011-08-18 | John David Newton | Activating Features on an Imaging Device Based on Manipulations |
US20110221666A1 (en) * | 2009-11-24 | 2011-09-15 | Not Yet Assigned | Methods and Apparatus For Gesture Recognition Mode Control |
WO2011069152A2 (en) * | 2009-12-04 | 2011-06-09 | Next Holdings Limited | Imaging methods and systems for position detection |
US9329700B2 (en) | 2010-01-14 | 2016-05-03 | Smart Technologies Ulc | Interactive system with successively activated illumination sources |
US20110234542A1 (en) * | 2010-03-26 | 2011-09-29 | Paul Marson | Methods and Systems Utilizing Multiple Wavelengths for Position Detection |
TW201203052A (en) | 2010-05-03 | 2012-01-16 | Flatfrog Lab Ab | Touch determination by tomographic reconstruction |
CN102270063B (en) * | 2010-06-03 | 2016-01-20 | 上海优熠电子科技有限公司 | Infrared true multi-point touch screen |
KR20130109090A (en) | 2010-06-11 | 2013-10-07 | 쓰리엠 이노베이티브 프로퍼티즈 컴파니 | Positional touch sensor with force measurement |
CN102402339B (en) * | 2010-09-07 | 2014-11-05 | 北京汇冠新技术股份有限公司 | Touch positioning method, touch screen, touch system and display |
EP2447811B1 (en) | 2010-11-02 | 2019-12-18 | LG Display Co., Ltd. | Infrared sensor module, touch sensing method thereof, and auto calibration method applied to the same |
CN102692182A (en) * | 2011-03-23 | 2012-09-26 | 刘中华 | Optical detection system used for screen touch control input device |
WO2013062471A2 (en) * | 2011-10-27 | 2013-05-02 | Flatfrog Laboratories Ab | Touch determination by tomographic reconstruction |
TWI454995B (en) * | 2011-08-11 | 2014-10-01 | Wistron Corp | Optical touch device and coordinate detection method thereof |
TW201329821A (en) * | 2011-09-27 | 2013-07-16 | Flatfrog Lab Ab | Image reconstruction for touch determination |
CN102622137B (en) * | 2012-02-29 | 2014-12-03 | 广东威创视讯科技股份有限公司 | Touch screen multi-point touch control method and device for front positioning of cameras |
JP6216776B2 (en) * | 2012-04-30 | 2017-10-18 | ラプト アイピー リミテッド | Multi-touch event detection in optical touch-sensitive devices using touch event templates |
KR101690205B1 (en) * | 2012-11-30 | 2016-12-27 | 랩트 아이피 리미티드 | Optical Touch Tomography |
WO2015006125A1 (en) * | 2013-07-08 | 2015-01-15 | Elo Touch Solutions, Inc. | Multi-user multi-touch projected capacitance touch sensor |
CN103885648B (en) * | 2014-03-25 | 2017-04-12 | 锐达互动科技股份有限公司 | True two-point touch detecting method for side projection double-lens touch screen |
TWI529583B (en) | 2014-12-02 | 2016-04-11 | 友達光電股份有限公司 | Touch system and touch detection method |
CN105278668A (en) * | 2014-12-16 | 2016-01-27 | 维沃移动通信有限公司 | Mobile terminal control method and mobile terminal |
TWI562046B (en) * | 2015-06-25 | 2016-12-11 | Wistron Corp | Optical touch apparatus and width detecting method thereof |
EP3743179B1 (en) | 2018-01-25 | 2023-08-09 | Neonode Inc. | Spherical coordinate sensor for vehicle occupant monitoring |
KR102009977B1 (en) * | 2018-04-25 | 2019-10-21 | (주)에이치엠솔루션 | Multimedia indoor sports game system |
CN109361864B (en) * | 2018-11-20 | 2020-07-10 | 维沃移动通信(杭州)有限公司 | Shooting parameter setting method and terminal equipment |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020145595A1 (en) * | 2001-03-26 | 2002-10-10 | Mitsuru Satoh | Information input/output apparatus, information input/output control method, and computer product |
US20060012579A1 (en) * | 2004-07-14 | 2006-01-19 | Canon Kabushiki Kaisha | Coordinate input apparatus and its control method |
US20060232830A1 (en) * | 2005-04-15 | 2006-10-19 | Canon Kabushiki Kaisha | Coordinate input apparatus, control method therefore, and program |
US20100045629A1 (en) * | 2008-02-11 | 2010-02-25 | Next Holdings Limited | Systems For Resolving Touch Points for Optical Touchscreens |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
BE1003136A3 (en) * | 1990-03-23 | 1991-12-03 | Icos Vision Systems Nv | METHOD AND APPARATUS FOR DETERMINING A POSITION OF AT LEAST ONE CONNECTION OF AN ELECTRONIC COMPONENT |
US5635724A (en) * | 1995-06-07 | 1997-06-03 | Intecolor | Method and apparatus for detecting the location of an object on a surface |
JP3830121B2 (en) * | 1999-06-10 | 2006-10-04 | 株式会社 ニューコム | Optical unit for object detection and position coordinate input device using the same |
US6690363B2 (en) * | 2000-06-19 | 2004-02-10 | Next Holdings Limited | Touch panel display system |
WO2003071410A2 (en) * | 2002-02-15 | 2003-08-28 | Canesta, Inc. | Gesture recognition system using depth perceptive sensors |
JP2003303046A (en) * | 2002-04-11 | 2003-10-24 | Ricoh Elemex Corp | Optical coordinate detection device |
JP4522113B2 (en) | 2004-03-11 | 2010-08-11 | キヤノン株式会社 | Coordinate input device |
JP4429047B2 (en) * | 2004-03-11 | 2010-03-10 | キヤノン株式会社 | Coordinate input device, control method therefor, and program |
US7538759B2 (en) * | 2004-05-07 | 2009-05-26 | Next Holdings Limited | Touch panel display system with illumination and detection provided from a single edge |
US7538894B2 (en) * | 2005-04-15 | 2009-05-26 | Canon Kabushiki Kaisha | Coordinate input apparatus, control method thereof, and program |
JP4455392B2 (en) * | 2005-04-15 | 2010-04-21 | キヤノン株式会社 | Coordinate input device, control method therefor, and program |
US7599520B2 (en) * | 2005-11-18 | 2009-10-06 | Accenture Global Services Gmbh | Detection of multiple targets on a plane of interest |
CN101479691B (en) * | 2006-06-28 | 2011-12-14 | 皇家飞利浦电子股份有限公司 | Method and apparatus for object learning and recognition based on optical parameters |
US7932899B2 (en) * | 2009-09-01 | 2011-04-26 | Next Holdings Limited | Determining the location of touch points in a position detection system |
US20110199387A1 (en) * | 2009-11-24 | 2011-08-18 | John David Newton | Activating Features on an Imaging Device Based on Manipulations |
US20110199335A1 (en) * | 2010-02-12 | 2011-08-18 | Bo Li | Determining a Position of an Object Using a Single Camera |
-
2009
- 2009-02-10 US US12/368,372 patent/US20090219256A1/en not_active Abandoned
- 2009-02-10 KR KR1020107020283A patent/KR20100121512A/en not_active Application Discontinuation
- 2009-02-10 WO PCT/US2009/033624 patent/WO2009102681A2/en active Application Filing
- 2009-02-10 CN CN200980108845XA patent/CN101971129A/en active Pending
- 2009-02-10 EP EP09711050A patent/EP2250546A2/en not_active Withdrawn
- 2009-11-06 US US12/613,956 patent/US20100045629A1/en not_active Abandoned
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020145595A1 (en) * | 2001-03-26 | 2002-10-10 | Mitsuru Satoh | Information input/output apparatus, information input/output control method, and computer product |
US20060012579A1 (en) * | 2004-07-14 | 2006-01-19 | Canon Kabushiki Kaisha | Coordinate input apparatus and its control method |
US20060232830A1 (en) * | 2005-04-15 | 2006-10-19 | Canon Kabushiki Kaisha | Coordinate input apparatus, control method therefore, and program |
US20100045629A1 (en) * | 2008-02-11 | 2010-02-25 | Next Holdings Limited | Systems For Resolving Touch Points for Optical Touchscreens |
Cited By (103)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8466885B2 (en) | 2003-02-14 | 2013-06-18 | Next Holdings Limited | Touch screen signal processing |
US8456447B2 (en) | 2003-02-14 | 2013-06-04 | Next Holdings Limited | Touch screen signal processing |
US8508508B2 (en) | 2003-02-14 | 2013-08-13 | Next Holdings Limited | Touch screen signal processing with single-point calibration |
US8289299B2 (en) | 2003-02-14 | 2012-10-16 | Next Holdings Limited | Touch screen signal processing |
US8149221B2 (en) | 2004-05-07 | 2012-04-03 | Next Holdings Limited | Touch panel display system with illumination and detection provided from a single edge |
US8115753B2 (en) | 2007-04-11 | 2012-02-14 | Next Holdings Limited | Touch screen system with hover and click input methods |
US8384693B2 (en) | 2007-08-30 | 2013-02-26 | Next Holdings Limited | Low profile touch panel systems |
US8432377B2 (en) | 2007-08-30 | 2013-04-30 | Next Holdings Limited | Optical touchscreen with improved illumination |
US8405637B2 (en) | 2008-01-07 | 2013-03-26 | Next Holdings Limited | Optical position sensing system and optical position sensor assembly with convex imaging window |
US8405636B2 (en) | 2008-01-07 | 2013-03-26 | Next Holdings Limited | Optical position sensing system and optical position sensor assembly |
US20100045629A1 (en) * | 2008-02-11 | 2010-02-25 | Next Holdings Limited | Systems For Resolving Touch Points for Optical Touchscreens |
US9134854B2 (en) | 2008-06-23 | 2015-09-15 | Flatfrog Laboratories Ab | Detecting the locations of a plurality of objects on a touch surface |
US20110090176A1 (en) * | 2008-06-23 | 2011-04-21 | Flatfrog Laboratories Ab | Determining the location of one or more objects on a touch surface |
US20110074734A1 (en) * | 2008-06-23 | 2011-03-31 | Ola Wassvik | Detecting the location of an object on a touch surface |
US20110163996A1 (en) * | 2008-06-23 | 2011-07-07 | Ola Wassvik | Determining the location of one or more objects on a touth surface |
US8890843B2 (en) | 2008-06-23 | 2014-11-18 | Flatfrog Laboratories Ab | Detecting the location of an object on a touch surface |
US8482547B2 (en) * | 2008-06-23 | 2013-07-09 | Flatfrog Laboratories Ab | Determining the location of one or more objects on a touch surface |
US20110074735A1 (en) * | 2008-06-23 | 2011-03-31 | Flatfrog Laboratories Ab | Detecting the locations of a plurality of objects on a touch surface |
US9552104B2 (en) | 2008-08-07 | 2017-01-24 | Rapt Ip Limited | Detecting multitouch events in an optical touch-sensitive device using touch event templates |
US20190163325A1 (en) * | 2008-08-07 | 2019-05-30 | Rapt Ip Limited | Detecting multitouch events in an optical touch-sensitive device using touch event templates |
US10795506B2 (en) * | 2008-08-07 | 2020-10-06 | Rapt Ip Limited | Detecting multitouch events in an optical touch- sensitive device using touch event templates |
US20120212458A1 (en) * | 2008-08-07 | 2012-08-23 | Rapt Ip Limited | Detecting Multitouch Events in an Optical Touch-Sensitive Device by Combining Beam Information |
US8531435B2 (en) * | 2008-08-07 | 2013-09-10 | Rapt Ip Limited | Detecting multitouch events in an optical touch-sensitive device by combining beam information |
US10067609B2 (en) | 2008-08-07 | 2018-09-04 | Rapt Ip Limited | Detecting multitouch events in an optical touch-sensitive device using touch event templates |
US9092092B2 (en) | 2008-08-07 | 2015-07-28 | Rapt Ip Limited | Detecting multitouch events in an optical touch-sensitive device using touch event templates |
US20100090986A1 (en) * | 2008-10-15 | 2010-04-15 | Yanfeng Wang | Multi-touch positioning method and multi-touch screen |
US20140085268A1 (en) * | 2008-10-15 | 2014-03-27 | Beijing Boe Optoelectronics Technology Co., Ltd. | Multi-touch positioning method and multi-touch screen |
US8619060B2 (en) * | 2008-10-15 | 2013-12-31 | Beijing Boe Optoelectronics Technology Co., Ltd. | Multi-touch positioning method and multi-touch screen |
US9542044B2 (en) * | 2008-10-15 | 2017-01-10 | Beijing Boe Optoelectronics Technology Co., Ltd. | Multi-touch positioning method and multi-touch screen |
US10474249B2 (en) | 2008-12-05 | 2019-11-12 | Flatfrog Laboratories Ab | Touch sensing apparatus and method of operating the same |
US20100207912A1 (en) * | 2009-02-13 | 2010-08-19 | Arima Lasers Corp. | Detection module and an optical detection system comprising the same |
US20100245292A1 (en) * | 2009-03-31 | 2010-09-30 | Arima Lasers Corp. | Optical detection apparatus and method |
US20100302207A1 (en) * | 2009-05-27 | 2010-12-02 | Lan-Rong Dung | Optical Touch Control Method and Apparatus Thereof |
US20110050649A1 (en) * | 2009-09-01 | 2011-03-03 | John David Newton | Determining the Location of Touch Points in a Position Detection System |
US7932899B2 (en) | 2009-09-01 | 2011-04-26 | Next Holdings Limited | Determining the location of touch points in a position detection system |
US20110116104A1 (en) * | 2009-11-16 | 2011-05-19 | Pixart Imaging Inc. | Locating Method of Optical Touch Device and Optical Touch Device |
US20110115746A1 (en) * | 2009-11-16 | 2011-05-19 | Smart Technologies Inc. | Method for determining the location of a pointer in a pointer input region, and interactive input system executing the method |
US8994693B2 (en) * | 2009-11-16 | 2015-03-31 | Pixart Imaging Inc. | Locating method of optical touch device and optical touch device |
US8446392B2 (en) * | 2009-11-16 | 2013-05-21 | Smart Technologies Ulc | Method for determining the location of a pointer in a pointer input region, and interactive input system executing the method |
US9280237B2 (en) * | 2009-11-17 | 2016-03-08 | Zetta Research and Development LLC—RPO Series | Apparatus and method for receiving a touch input |
US20120223916A1 (en) * | 2009-11-17 | 2012-09-06 | Dax Kukulj | Apparatus and method for receiving a touch input |
US20110109565A1 (en) * | 2010-02-04 | 2011-05-12 | Hong Kong Applied Science And Technology Research Institute Co. Ltd. | Cordinate locating method, coordinate locating device, and display apparatus comprising the coordinate locating device |
US20110116105A1 (en) * | 2010-02-04 | 2011-05-19 | Hong Kong Applied Science and Technology Research Institute Company Limited | Coordinate locating method and apparatus |
US8711125B2 (en) * | 2010-02-04 | 2014-04-29 | Hong Kong Applied Science And Technology Research Institute Co. Ltd. | Coordinate locating method and apparatus |
US8937612B2 (en) | 2010-02-04 | 2015-01-20 | Hong Kong Applied Science And Technology Research Institute Co. Ltd. | Coordinate locating method, coordinate locating device, and display apparatus comprising the coordinate locating device |
US8338725B2 (en) | 2010-04-29 | 2012-12-25 | Au Optronics Corporation | Camera based touch system |
US20110298708A1 (en) * | 2010-06-07 | 2011-12-08 | Microsoft Corporation | Virtual Touch Interface |
US20110316813A1 (en) * | 2010-06-23 | 2011-12-29 | Ren-Hau Gu | Optical touch display |
US20120050224A1 (en) * | 2010-08-24 | 2012-03-01 | Quanta Computer Inc. | Optical touch system and method |
US8692804B2 (en) * | 2010-08-24 | 2014-04-08 | Quanta Computer Inc. | Optical touch system and method |
US8704802B2 (en) * | 2010-10-12 | 2014-04-22 | Au Optronics Corporation | Touch display device |
US9052780B2 (en) * | 2010-10-20 | 2015-06-09 | Pixart Imaging Inc. | Optical touch screen system and sensing method for the same |
US20120098795A1 (en) * | 2010-10-20 | 2012-04-26 | Pixart Imaging Inc. | Optical touch screen system and sensing method for the same |
US9395849B2 (en) * | 2010-11-26 | 2016-07-19 | Beijing Irtouch Systems Co., Ltd | Infrared touch screen multi-point recognizing method and infrared touch screen |
US20130234993A1 (en) * | 2010-11-26 | 2013-09-12 | Haibing Zhang | Infrared touch screen multi-point recognizing method and infrared touch screen |
CN102479002A (en) * | 2010-11-30 | 2012-05-30 | 原相科技股份有限公司 | Optical touch control system and sensing method thereof |
US9019241B2 (en) * | 2011-02-15 | 2015-04-28 | Wistron Corporation | Method and system for generating calibration information for an optical imaging touch display device |
US20120206410A1 (en) * | 2011-02-15 | 2012-08-16 | Hsun-Hao Chang | Method and system for generating calibration information for an optical imaging touch display device |
JP2013025710A (en) * | 2011-07-25 | 2013-02-04 | Canon Inc | Coordinate input device and method for controlling the same, and program |
US9372546B2 (en) | 2011-08-12 | 2016-06-21 | The Research Foundation For The State University Of New York | Hand pointing estimation for human computer interaction |
US8971572B1 (en) | 2011-08-12 | 2015-03-03 | The Research Foundation For The State University Of New York | Hand pointing estimation for human computer interaction |
US20140015805A1 (en) * | 2012-01-04 | 2014-01-16 | Nexio Co., Ltd. | Infrared rays touch screen apparatus using array of infrared rays elements in two opposite sides |
US10168835B2 (en) | 2012-05-23 | 2019-01-01 | Flatfrog Laboratories Ab | Spatial resolution in touch displays |
US20140125588A1 (en) * | 2012-11-02 | 2014-05-08 | Wistron Corp. | Electronic device and operation method thereof |
US20140253512A1 (en) * | 2013-03-11 | 2014-09-11 | Hitachi Maxell, Ltd. | Manipulation detection apparatus, manipulation detection method, and projector |
US10152177B2 (en) * | 2013-03-11 | 2018-12-11 | Maxell, Ltd. | Manipulation detection apparatus, manipulation detection method, and projector |
US10019113B2 (en) | 2013-04-11 | 2018-07-10 | Flatfrog Laboratories Ab | Tomographic processing for touch detection |
US9874978B2 (en) | 2013-07-12 | 2018-01-23 | Flatfrog Laboratories Ab | Partial detect mode |
US10146376B2 (en) | 2014-01-16 | 2018-12-04 | Flatfrog Laboratories Ab | Light coupling in TIR-based optical touch systems |
US10126882B2 (en) | 2014-01-16 | 2018-11-13 | Flatfrog Laboratories Ab | TIR-based optical touch systems of projection-type |
US9395848B2 (en) * | 2014-04-30 | 2016-07-19 | Quanta Computer Inc. | Optical touch control systems and methods thereof |
US10161886B2 (en) | 2014-06-27 | 2018-12-25 | Flatfrog Laboratories Ab | Detection of surface contamination |
US11182023B2 (en) | 2015-01-28 | 2021-11-23 | Flatfrog Laboratories Ab | Dynamic touch quarantine frames |
US10318074B2 (en) | 2015-01-30 | 2019-06-11 | Flatfrog Laboratories Ab | Touch-sensing OLED display with tilted emitters |
US10496227B2 (en) | 2015-02-09 | 2019-12-03 | Flatfrog Laboratories Ab | Optical touch system comprising means for projecting and detecting light beams above and inside a transmissive panel |
US11029783B2 (en) | 2015-02-09 | 2021-06-08 | Flatfrog Laboratories Ab | Optical touch system comprising means for projecting and detecting light beams above and inside a transmissive panel |
US10401546B2 (en) | 2015-03-02 | 2019-09-03 | Flatfrog Laboratories Ab | Optical component for light coupling |
US11301089B2 (en) | 2015-12-09 | 2022-04-12 | Flatfrog Laboratories Ab | Stylus identification |
US10761657B2 (en) | 2016-11-24 | 2020-09-01 | Flatfrog Laboratories Ab | Automatic optimisation of touch signal |
US11281335B2 (en) | 2016-12-07 | 2022-03-22 | Flatfrog Laboratories Ab | Touch device |
US10282035B2 (en) | 2016-12-07 | 2019-05-07 | Flatfrog Laboratories Ab | Touch device |
US10775935B2 (en) | 2016-12-07 | 2020-09-15 | Flatfrog Laboratories Ab | Touch device |
US11579731B2 (en) | 2016-12-07 | 2023-02-14 | Flatfrog Laboratories Ab | Touch device |
US11740741B2 (en) | 2017-02-06 | 2023-08-29 | Flatfrog Laboratories Ab | Optical coupling in touch-sensing systems |
US11474644B2 (en) | 2017-02-06 | 2022-10-18 | Flatfrog Laboratories Ab | Optical coupling in touch-sensing systems |
US10606414B2 (en) | 2017-03-22 | 2020-03-31 | Flatfrog Laboratories Ab | Eraser for touch displays |
US10481737B2 (en) | 2017-03-22 | 2019-11-19 | Flatfrog Laboratories Ab | Pen differentiation for touch display |
US11016605B2 (en) | 2017-03-22 | 2021-05-25 | Flatfrog Laboratories Ab | Pen differentiation for touch displays |
US11099688B2 (en) | 2017-03-22 | 2021-08-24 | Flatfrog Laboratories Ab | Eraser for touch displays |
US11269460B2 (en) | 2017-03-28 | 2022-03-08 | Flatfrog Laboratories Ab | Touch sensing apparatus and method for assembly |
US10437389B2 (en) | 2017-03-28 | 2019-10-08 | Flatfrog Laboratories Ab | Touch sensing apparatus and method for assembly |
US11281338B2 (en) | 2017-03-28 | 2022-03-22 | Flatfrog Laboratories Ab | Touch sensing apparatus and method for assembly |
US10739916B2 (en) | 2017-03-28 | 2020-08-11 | Flatfrog Laboratories Ab | Touch sensing apparatus and method for assembly |
US10845923B2 (en) | 2017-03-28 | 2020-11-24 | Flatfrog Laboratories Ab | Touch sensing apparatus and method for assembly |
US10606416B2 (en) | 2017-03-28 | 2020-03-31 | Flatfrog Laboratories Ab | Touch sensing apparatus and method for assembly |
US12086362B2 (en) | 2017-09-01 | 2024-09-10 | Flatfrog Laboratories Ab | Optical component |
US11256371B2 (en) | 2017-09-01 | 2022-02-22 | Flatfrog Laboratories Ab | Optical component |
US11650699B2 (en) | 2017-09-01 | 2023-05-16 | Flatfrog Laboratories Ab | Optical component |
US11567610B2 (en) | 2018-03-05 | 2023-01-31 | Flatfrog Laboratories Ab | Detection line broadening |
US12055969B2 (en) | 2018-10-20 | 2024-08-06 | Flatfrog Laboratories Ab | Frame for a touch-sensitive device and tool therefor |
US11943563B2 (en) | 2019-01-25 | 2024-03-26 | FlatFrog Laboratories, AB | Videoconferencing terminal and method of operating the same |
US12056316B2 (en) | 2019-11-25 | 2024-08-06 | Flatfrog Laboratories Ab | Touch-sensing apparatus |
US11893189B2 (en) | 2020-02-10 | 2024-02-06 | Flatfrog Laboratories Ab | Touch-sensing apparatus |
Also Published As
Publication number | Publication date |
---|---|
US20100045629A1 (en) | 2010-02-25 |
KR20100121512A (en) | 2010-11-17 |
WO2009102681A3 (en) | 2010-05-14 |
WO2009102681A2 (en) | 2009-08-20 |
EP2250546A2 (en) | 2010-11-17 |
CN101971129A (en) | 2011-02-09 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20090219256A1 (en) | Systems and Methods for Resolving Multitouch Scenarios for Optical Touchscreens | |
US20090278816A1 (en) | Systems and Methods For Resolving Multitouch Scenarios Using Software Filters | |
US8432377B2 (en) | Optical touchscreen with improved illumination | |
EP2353069B1 (en) | Stereo optical sensors for resolving multi-touch in a touch detection system | |
US9645679B2 (en) | Integrated light guide and touch screen frame | |
US8384693B2 (en) | Low profile touch panel systems | |
US8711125B2 (en) | Coordinate locating method and apparatus | |
US8115753B2 (en) | Touch screen system with hover and click input methods | |
US9367177B2 (en) | Method and system for determining true touch points on input touch panel using sensing modules | |
TWI498785B (en) | Touch sensor apparatus and touch point detection method | |
TWI520034B (en) | Method of determining touch gesture and touch control system | |
US20110234542A1 (en) | Methods and Systems Utilizing Multiple Wavelengths for Position Detection | |
JP2005004278A (en) | Coordinate input device | |
JP5934216B2 (en) | System and method for detecting and tracking radiation shielding objects on a surface | |
TW201312421A (en) | Optical touch panel system, optical apparatus and positioning method thereof | |
KR101359731B1 (en) | System for recognizing touch-point using mirror | |
TWI525507B (en) | Optical touch system, method of touch detection, and computer program product | |
US8912482B2 (en) | Position determining device and method for objects on a touch device having a stripped L-shaped reflecting mirror and a stripped retroreflector | |
TWI518575B (en) | Optical touch module | |
CN111488068B (en) | Optical touch device and optical touch method | |
JP2021026333A (en) | Position indication device, display system, position indication method, and program | |
TW201433964A (en) | Optical touch panel system, optical apparatus and positioning method thereof |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: NEXT HOLDINGS LIMITED, NEW ZEALAND Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:NEWTON, JOHN DAVID;REEL/FRAME:022695/0908 Effective date: 20090518 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |